Electric power converting device, and electricity generating system

An electric power conversion device configured to be connected to a power system through interconnection impedance, comprising:

• a converter of which a switch is switched at a predetermined switching cycle, and which outputs power to the power system through the interconnection impedance;
• a voltage detector that detects an interconnection point voltage between the electric power conversion device and the power system;
• and
• a control device that controls the converter on the basis of a moving average of an output voltage of the voltage detector over a predetermined period in correspondence with the switching cycle,
• wherein the control device sets a value of real-number multiple of the output voltage as an active current command value.

An electric power conversion device configured to be connected to a power system through interconnection impedance, comprising:

• a converter of which a switch is switched at a predetermined switching cycle, and which outputs power to the power system through the interconnection impedance;
• a voltage detector that detects an interconnection point voltage between the electric power conversion device and the power system;
• and
• a control device that controls the converter on the basis of a moving average of an output voltage of the voltage detector over a predetermined period in correspondence with the switching cycle,
• wherein the control device sets a value of a real-number multiple of the output voltage as a current command value, calculates an instantaneous voltage on the basis of the current command value, and generates a voltage command value of the converter from the instantaneous voltage.

An electric power conversion device configured to be connected to a system functioning as an AC voltage source through interconnection impedance, comprising:

• a converter that includes a switch that is switched to output pulses of different widths at approximately constant cycles, and outputs a predetermined AC voltage;
• a voltage detector that detects a system voltage of the system;
• and
• a control device that controls the converter,
• wherein the voltage detector includes a detection unit that detects a voltage value at a predetermined point of the system to which the converter is connected, and a filtering unit that moving-averages an output voltage of the detection unit or calculates an approximate value of a moving average of the output voltage over a period of one cycle or several cycles of constant cycles, and
• the control device includes a voltage command value generation unit that adds at least one or more of an active power component voltage command value for outputting active power and a reactive power component voltage command value for outputting reactive power to the system voltage to calculate a voltage command value.

An electric power conversion device configured to be connected to a power system through interconnection impedance, comprising:

• a converter that outputs a predetermined AC voltage;
• a system voltage detection device that detects a system voltage of the power system;
• and
• a control device that controls the converter by pulse width modulation control,
• wherein the system voltage detection device detects the system voltage by calculating a moving average over a period of one cycle or several cycles of a carrier wave used in the pulse width modulation control with respect to a detected voltage,
• the control device has a function of calculating a voltage command value of the converter on the basis of the system voltage calculated by moving-averaging, and
• the control device includes a voltage command value generation unit that adds at least one or more of an active power component voltage command value for outputting active power and a reactive power component voltage command value for outputting reactive power to the system voltage to calculate a voltage command value.

An electric power conversion device configured to be connected to a power system through interconnection impedance, comprising:

• a converter that outputs a predetermined AC voltage;
• a system voltage detection device that detects a system voltage of the power system;
• and
• a control device that controls the converter by pulse width modulation control,
• wherein the system voltage detection device detects the system voltage by calculating a moving average over a period of one cycle or several cycles of a carrier wave used in the pulse width modulation control with respect to a detected voltage,
• the control device has a function of calculating a voltage command value of the converter on the basis of the system voltage calculated by moving-averaging, and
• the control device is a vector control unit that calculates the voltage command value by vector control on the basis of the system voltage.

An electric power conversion device configured to be connected to a power system through interconnection impedance, comprising:

• a converter that outputs a predetermined AC voltage;
• a system voltage detection device that detects a system voltage of the power system;
• and
• a control device that controls the converter by pulse width modulation control,
• wherein the system voltage detection device detects the system voltage by calculating a moving average over a period of one cycle or several cycles of a carrier wave used in the pulse width modulation control with respect to a detected voltage,
• the control device has a function of calculating a voltage command value of the converter on the basis of the system voltage calculated by moving-averaging, and
• the electric power conversion device further comprising:
• a voltage compensation unit that calculates a peak value of the system voltage, and adds a difference between a rated voltage of the power system and the peak value to the system voltage to compensate a difference between the system voltage and the rated voltage.

An electric power conversion device configured to be connected to a system functioning as an AC voltage source through interconnection impedance, comprising:

• a converter that includes a switch that is switched to output pulses of different widths at approximately constant cycles, and outputs a predetermined AC voltage;
• a voltage detector that detects a system voltage of the system;
• and
• a control device that controls the converter,
• wherein the voltage detector includes a detection unit that detects a voltage value at a predetermined point of the system to which the converter is connected, and a filtering unit that moving-averages an output voltage of the detection unit or calculates an approximate value of a moving average of the output voltage over a period of one cycle or several cycles of constant cycles,
• the control device has a function of calculating a voltage command value of the converter on the basis of the system voltage calculated by moving-averaging, and
• a value of a real-number multiple of the system voltage is set as a current command value.

An electric power conversion device configured to be connected to a system functioning as an AC voltage source through interconnection impedance, comprising:

• a converter that includes a switch that is switched to output pulses of different widths at approximately constant cycles, and outputs a predetermined AC voltage;
• a voltage detector that detects a system voltage of the system;
• and
• a control device that controls the converter,
• wherein the voltage detector includes a detection unit that detects a voltage value at a predetermined point of the system to which the converter is connected, and a filtering unit that moving-averages an output voltage of the detection unit or calculates an approximate value of a moving average of the output voltage over a period of one cycle or several cycles of constant cycles, and
• the electric power conversion device further comprising:
• a differential operation unit that calculates a product of a differential value or an inexact differential value of the system voltage multiplied by a real number and an inductance value of the interconnection impedance.

An electric power conversion device configured to be connected to a system functioning as an AC voltage source through interconnection impedance, comprising:

• a converter that includes a switch that is switched to output pulses of different widths at approximately constant cycles, and outputs a predetermined AC voltage;
• a voltage detector that detects a system voltage of the system;
• and
• a control device that controls the converter,
• wherein the voltage detector includes a detection unit that detects a voltage value at a predetermined point of the system to which the converter is connected, and a filtering unit that moving-averages an output voltage of the detection unit or calculates an approximate value of a moving average of the output voltage over a period of one cycle or several cycles of constant cycles, and
• the electric power conversion device further comprising:
• a differential operation unit that calculates a product of a differential value or an inexact differential value of the system voltage which is multiplied by a real number and in which a phase is advanced by 90° or delayed by 90°, and an inductance value of the interconnection impedance.